Integrated circuit fabrication is an enormously complex process, in which a wide range of materials, process, equipment, and know-how are brought together to form a product. Because the size of modern integrated circuits is so small, and because their design constraints are so tight, the devices themselves are easily impacted by any variations in the various factors listed above that are combined to produce them. Often, the impact on the integrated circuits is negative, costing the manufacturers millions of dollars in lost devices and productivity.
As integrated circuit fabrication costs continue to rise, yield management has become increasingly vital in helping manufacturers accelerate the ramp of new processes and technologies into production, in a manner where they can remain competitive and meet their profit margins. Finding defects and process errors during production is an important step in maximizing yield. Of equal importance, however, is finding the source of these yield problems so that corrective action can be taken quickly to optimize the processes. This is especially true for foundries, which implement many different processes and integrated circuit designs into production.
Yield management is typically implemented on computer based systems, on which an engineer can import data which they desire to investigate, and analyze the data using any one of a number of different routines that are provided by the yield management software. The results of those analysis procedures can be reported by whatever charting and display options are available in the yield management package.
Unfortunately, there are many drawbacks to currently available yield management systems. For example, yield management systems tend to have predefined capabilities, which either cannot be changed at all, or require additional development level work to change. Such rigidity can be seen in many aspects of the yield management system, such as in the analysis routines, the data input options, and the reporting options.
In regard to analysis, many integrated circuit manufacturers desire to use certain analysis procedures in their in their data analysis processes, which sets of analysis procedures tend to different from manufacturer to manufacturer. Thus, a single suite of analysis routines in a yield management system is insufficient. Further, some manufacturers desire to use customized and proprietary routines, which they do not wish to divulge to outside parties. Such routines cannot be added by the user to currently available yield management systems.
Similar limitations apply to the issue of data input. The integrated circuit fabrication process produces an enormous amount of data from an equally enormous number of different sources. Many of these data sources tend to have their own data storage architecture. Again, current yield management systems are insufficient in their ability to read all of the different data architectures that are available. Further, to build such “universal” ability into a yield management system would be cumbersome and awkward at best, and would be quickly outdated.
These limitations are also applicable to data reporting options. The number of different reporting options available, and the different preferences which exist from one manufacturer to another, tends to make it impossible to offer everyone the exact options that they desire in a traditional yield management system.
Thus, there are many shortcomings in the yield management systems that are currently offered. What is needed, therefore, is a yield management system with an architecture that reduces at least some of the problems with current yield management systems.